"There's just one problem. He forgot about what he had done in Scotland. When George Osborne handed him the plans to make cuts to capital spending of 11%, he didn’t just make those cuts. He almost doubled them."

He added: "If you want to create a country that is really a progressive beacon, why would you abandon the redistributive union that is the United Kingdom?

"I believe, and I believe that people across the United Kingdom believe, that we owe obligations to each other, that the successful Scottish entrepreneur owes obligations to the child born into poverty in London and the pensioner in Wales.

"Right now, every nation of the UK needs not isolation but solidarity."

Meanwhile, in Inverness, Liberal Democrat leader Mr Clegg argued the nationalists still have questions to answer about the practical problems with an independent Scotland.

The deputy prime minister also demanded the referendum be held "sooner, rather than later" and ask one simple question on independence – leaving out a third 'devo-max' option.